Green’s Dictionary of Slang

rumadj.

alsorome[most prob. from SE Rome (and indeed could be spelled ‘rome’ until the 18C), which, as a city, meant glory and grandeur. Other origins include the Romany rom, a male gypsy, or the Turkish Röm, a gypsy, many of whom passed through the Ottoman Empire. Reversing the process, the Lat. Roma (Rome) is cognate with the Teutonic root hruod (fame) (as found in the names Roger and Roderick) which appears in the German Ruhm (fame)](orig. UK Und.)

[late 18C] (UK Und.) a thief who poses as a drunkard and persuades a carter to let him lead his horse while he gets some sleep; the ‘drunkard’ then re-addresses the parcels that are on the wagon, which will therefore be delivered to houses where his confederates can collect them .